Clamp operating mechanism for paper cutting machines and the like



Dec. 6, 1966 w c, P

CLAMP OPERATING MECHANISM FOR PAPER CUTTING MACHINES AND THE LIKE Original Filed April 6, 1962 5 Sheets-Sheet l INVEN TOR.

WILLIAM C. RUPP FIG 2 ATTORNEYS Dec. 6, 1966 w. c. RUPP 3,289,514

CLAMP OPERATING MECHANISM FOR PAPER CUTTING MACHINES AND THE LIKE Original Filed April 6, 1962 5 Sheets-Sheet 2 50 I I V I] g o 1 79 0 1 U] u 5 Q o O 88' 3 a E I F G 4 5 IN V EN TOR.

WILLIAM c. RUPP ATTORNEYS Dec. 6, 1966 'w. c. RUPP CLAMP OPERATING MECHANISM FOR PAPER CUTTING MACHINES AND THE LIKE Original Filed April 6, 1962 5 Sheets-Sheet 5 FIG 6 FIG 5 INVENTOR.

WILLIAM C RUPP FIG 7 aamwm? a ,0 ATT RNEYS United States Patent fifice 3,289,514 Patented Dec. 6, 1.966

3,289,514 CLAMP OPERATING MECHANISM FOR PAPER CUTTING MACHlNES AND THE LllKE William C. Rupp, lParrna, Uhio, assignor to The Chandler ghilrice Company, Cleveland, Uhio, a corporation of 10 Original application Apr. 6, 1962, Ser. No. 185,567, now Patent No. 3,233,492. Divided and this application May 26, 1965, Ser. No. 458,952

Claims. (Cl. 83-459) This is a division of application, Serial No. 185,567, filed April 6, 1962, entitled Hydraulic Paper Cutting Machine, now Patent No. 3,233,492.

This invention relates generally, as indicated, to a hydraulic paper cutting machine and more particularly to certain improvements simplifying the operation and increasing the safety of machines such as that disclosed in my prior copending application, Serial No. 862,841 entitled Automatic Gauge for Paper Cutting Machines and the Like, now Patent No. 3,111,876.

In hydraulic paper cutting machines, it has been found that as the parts thereof wear, there may develop a slow fluid leakage or seepage in the hydraulic system permitting the knife to drop slightly over a fairly long period of non-use, a week-end, for example, so that the cutting edge projects below the housing or encasement thereof beneath the bottom of the clamp in its elevated position. Under such circumstances, an incautious operator may cut the back of his hand on the slightly projecting blade, and it is desirable to provide a means for securing the blade in elevated position despite such fluid seepage.

In hydraulic paper cutting machines, it is sometimes desirable to bring down the clamp without affecting the knife. Heretofore, foot tripped valves have been employed making it possible for the operator to catch his fingers beneath the clamp. Accordingly, it is desirable to have a directly manually operable mechanism for urging the clamp downwardly irrespective of the hydraulic power mechanism connected thereto.

It is a principal object of the present invention to provide a hydraulic paper cutting machine having a hydraulically actuated knife which cannot move downwardly in its uppermost position due to hydraulic fluid seepage.

It is another main object to provide a hydraulic paper cutting machine wherein the knife will be mechanically supported independently of the hydraulic system when not in use.

A further main object is to provide a hydraulic paper cutting machine having a hydraulically operated clamp which can also be operated manually without disturbing the hydraulic power mechanism therefor.

Another object is the employment in such a machine of a manual override for the hydraulically operated clamp which will bring the clamp down in synchronism with continued downward movement of a manually operable lever.

A still further object is the provision in such a machine of a reduced capacity drive in combination with an energy storage means enabling a smaller less expensive motor to be employed than would otherwise be required.

A yet further object is the provision of a highly simplified control and drive mechanism for the operation of the clamp and cutter of a paper cutting machine.

Other objects and advantages of the present invention will become apparent as the following description preceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various Ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a fragmentary front elevation partially broken away and in section of a paper cutting machine in accordance with the present invention;

FIG. 2 is a fragmentary side elevation of such paper cutting machine on a somewhat reduced scale as seen from the left in FIG. 1;

FIG. 3 is a transverse section taken substantially on the line 3-3 of FIG. 1 showing the power unit of the present invention with certain other parts removed for clarity of illustration;

FIG. 4 is a transverse section taken substantially on the line 44 of FIG. 2 with the power unit removed for clarity of illustration showing the clamp actuating mechanism of the present invention;

FIG. 5 is a vertical section taken substantially on the line 55 of FIG. 4 ilustrating the manual clamp operating mechanism in one position;

FIG. 6 is a vertical section similar to that of FIG. 5 showing the manual clamp operating mechanism in an alternative position; and

FIG. 7 is a schematic electric and hydraulic diagram illustrating the operation of the present invention.

Referring now to the annexed drawings and more particularly to FIGS. 1 and 2, the general construction of the paper cutting machine illustrated will first be described, such machine being similar to that disclosed in my Patent No. 2,781,093 and my aforementioned copending application, Serial No. 862,841, filed December 30, 1959 for Automatic Gauge for Paper Cutting Machines and the Like, for example. Such machine comprises a cast iron base 1 providing an upstanding support for a table 2 having a top paper stack receiving surface 3 extending between uprights 4 and 5 joined by an upper frame or head member 6. A back gauge 7 may be adjusted forwardly or rearwardly along the top surface 3 of the table 2 by means of a hand wheel 8. Side gauges 9 are provided for lateral positioning of a stack of such papers.

The pairs of uprights 4 and 5 provide vertically extending guides for a horizontally extending knife bar 10 having a bottom paper cutting knife blade 11. Such knife bar 10 is supported for swinging movement on the head 6 by means of links 13 and 14 pivoted to the head and knife bar respectively. In the illustrated embodiment, the distance between the pivots of the link 13 will be slightly longer than the distance between the pivots of the link 14 to provide a rocking shearing action of the knife bar 10 as it descends about the link pivots 15 and 16 on the head 6.

The link 14 is provided with a laterally offset extension 17 distally pivotally connected at 18 to an adjustable connecting rod 19, the opposite end of which is pivotally connected at 20 to a bell crank type link 21 which is intermediately pivotally connected at 22 to a pair of projecting cars 23 on the side wall of the base 1. The opposite end of the crank link 21 is pivotally connected at 24 to rod 25 of knife actuating piston-cylinder assembly 26. The blind end of such piston-cylinder assembly is pivotally connected at 27 to projections 28 extending from the same side wall of the base 1.

When the knife bar 11) is in its FIG. 1 retracted full line position, it will normally be positioned above the lower edge of a binder clamp 31} which, like the knife bar 10, is mounted in the uprights 4 and '5 for guided ve tical movement. The binder clamp is thus adapted to be reciprocated vertically downwardly to clamp a stack of paper properly gauged directly rearwardly of the knife bar 111 which will properly sever such stack as the knife 3 bar is brought downwardly by extension of the pistoncylinder assembly 26.

In conventional paper cutting machines, the knife bar is generally held in its retracted position corresponding to the full line position shown in FIG. 1 by the fluid within the knife bar actuating piston-cylinder assembly. It has been found that in due course, as the parts of the machine Wear, there may develop slow fluid seepage in the hydraulic system of such piston-cylinder assembly permitting the knife to drop slightly after a relatively long period of time. Thus, for example, should an operator leave the machine over a week-end, he may return to find that the knife has dropped so that the cutting edge 11 projects below the binder clamp 39. This, however, may be only a very short distance and is not readily visibly ascertainable. Under such circumstances, an incautious operator may cut the back of his hand during the set-up operation not realizing the knife has dropped below the level of the binder clamp in its retracted position.

With the present invention, this safety hazard is precluded since the knife bar is mechanically propped up in its retracted full line position shown in FIG. 1 and the fluid in piston-cylinder assembly 26 is not required to keep the knife bar thus raised. In such full line position, the pivot Will be slightly to the right of the line drawn between pivots 18 and 22 and the rod will be bottomed in the piston-cylinder assembly 26. In this manner, the crank link 21 is precluded from rotating further in a clockwise direction as seen in FIG. 1 and the knife bar 19 is then mechanically propped up in its retracted position. When it is desired to make a cut, fluid will be supplied to the blind end of the pistoncylinder assembly causing the rod 25 to extend rocking the crank link 21 about the pivot 22 in a counterclockwise direction as seen in FIG. 1 moving the pivot 20 to the dotted line position shown at 32 swinging the knife bar downwardly about the pivots l5 and 16. When it is desired to elevate the knife to its retracted position, fluid will be supplied to the rod end of the piston-cylinder assembly 26 causing the crank link 21 to pivot in a clockwise direction about the pivot 22 moving the pivot 20 over center mechanically to prop the knife bar 10 in its retracted position. In this manner, the knife will be held in its retracted position regardless of any fluid pressure in the piston-cylinder assembly 26. This is, of course, accomplished by the employment of the bell crank 21 which pulls the knife down as the rod 25 is extended. This also permits the greater area on the blind end of the piston of the piston-cylinder 26 to be employed for the cutting action. Were the piston rod 25 connected directly to the link extension 17, it will be seen that fluid would have to be applied to the rod end of the piston and would thus be acting on a much less area. Accordingly, with the present invention, a smaller piston-cylinder assembly may be employed to obtain the same cutting pressure.

The binder clamp 30 is supported for vertical movement in the guideways afforded by the pairs of uprights 4 and 5 by a pair of operating links 34 and 35 (note FIGS. 2 and 4) which are pivoted at 36 and 37 respectively to links 38 and 39 keyed to clamp actuating shaft 40. Such binder clamp actuating shaft 40 is mounted for rotation in bushings All and 42 situated in specially formed sockets in the side walls of the cast iron base 1. The binder clamp actuating shaft 49 may be operated by two distinct mechanisms, one being the hydraulic piston-cylinder assembly 43 and the other being treadle 44 projecting through a slot 45 in the cover plate 46 fastened to the front of the cast iron base 1.

The blind end of the piston-cylinder assembly 43 may be pivoted at 48, such pivot being provided in the frame 49 for the drive unit shown in FIG. 3 and omitted in FIG. 4 for clarity of illustration. Such cast iron frame 49 may be provided with upstanding cars 50 provided with apertures to receive a pin providing such pivot 48. The frame 49, of course, will be secured to the bottom of the base 1 to provide a rigid structure. The rod 51 of the piston-cylinder assembly 43 is pivoted at 52 to a rocker link 53 freely rotatable on the shaft 40. The distal end of the rocker link is provided with a laterally offset projection 54- which overlies the projecting arm 55 of crank 56 keyed to shaft 49 as indicated at 57 (note FIGS. 5 and 6).

A rod 60 telescopically projecting into an aligned tube 61 is pivoted to the crank arm 55 as indicated at 62 and the tube 61 is :in turn pivoted to the drive unit frame 49 as shown at 63. A pair of compression springs 64 and 65 separated by collar 66 extends between a stop 67 on the rod 60 and a stop 68 on the tube 61. The employment of tWo compression springs as indicated is preferred because one single long compression spring, of course, tends to buckle. With the spring mechanism shown, the crank arm 55 and thus the shaft 40 will be resiliently held in the FIG. 5 position and in this position, the operating links 34 and 35 for the binder clamp will be in their raised or elevated position. Thus the spring mechanism tends to maintain the binder clamp in its uppermost position.

The treadle 44 comprises a plate adapted to be engaged by the operators foot mounted on the end of rebent arm 79 pivoted at 71 to the base 1. The arm is connected at 72 to a chain 73, the opposite end of which is connected to the outer end 74 of a crank link 75 keyed to shaft 4%. The operation of the binder clamp, either automatically hydraulically through the pistoncylinder assembly 43 or manually through the treadle 44, now becomes obvious.

During the setup operation, and for such setup purposes, it is often desirable preliminarily to bring the binder clamp down on the work. This, of course, in hydraulically operated cutters has been difficult to do without proceeding through a complete cycle of operation of the cutter. With the special lever and treadle arrangement shown more clearly in FIGS. 4, 5 and 6, it is then possible manually to depress the treadle 44 causing the chain 73 to pull the lever 75 downwardly rotating the shaft 40 which in turn rotates the crank arm 55 away from the lateral projection 54 on the rocker 53. In this manner, the springs 64 and 65 will be compressed and the links 34 and 35 will be brought downwardly bringing the binder clamp 30 therewith. As seen in FIGS. 4 and 5, the rocker 53 and the hydraulic piston-cylinder assembly 43 is unaffected by this treadle operation. It is also noted that as the treadle 44 descends and the springs 64 and 65 are compressed, the length of the moment arm through which the springs act on the shaft 40 decreases, moving from the FIG. 5 to the FIG. 6 position, with the net result being that a substantially uniform pressure may be applied to the treadle in all positions thereof. In other words, as the treadle descends, the moment arm of the force of the springs acting on the shaft 40 decreases even though the pressure of such springs acting on such shaft increases.

With the parts in their FIG. 5 position, it will be seen that the piston-cylinder assembly can readily extend the rod 51 to rock the rock lever about the shaft 40 causing the projection 54 to engage the lever arm 55 to rock the shaft 40 in the same manner as the depression of the treadle 44.

Referring now to the drive mechanism for the hydraulic system of the present invention seen more clearly in FIG. 3, it will be apparent that the frame 49 mounted in the base 1 provides a support for the pump 78 connected through coupling 79 to the shaft 80 of cast iron flywheel 81. Such shaft is mounted in pillow blocks 82 and 83. The projecting end of the shaft 80 is provided with a sheave 84' driven by belt 85 from the sheave 86 mounted on the shaft of motor 87. The pump 78 may be provided with an inlet 88 and an outlet 89 with the inlet being connected directly to the reservoir 90 shown in FIGS. 2 and 7. The transverse portion 91 of the frame 49 may be provided with a saddle indicated generally at 92 to receive a control valve 93 connected directly to the outlet of the pump. The flywheel 81 being of a substantial mass then acts as an energy storage means enabling a smaller less expensive motor 87 to be employed than would otherwise be required. For example, a 1% hp. motor can be employed properly to actuate the binder clamp and cutting bar through a cycle of operation instead of a 5 hp. motor which would otherwise be required. The flywheel is capable of storing suflicient energy to furnish adequate power to make the clamp and the cut during which the speed of the flywheel will be reduced, but which will still be suflicient so that it will regain its maximum speed before making the next cut during the next cycle of operation.

Referring now to FIG. 7, it will be seen that the control valve 93 may be operated by two solenoids 95 and 96 selectively to shift the spool of such valve supplying hydraulic fluid selectively from the pump outlet to the blind and rod ends of the clamp cylinder 43 and the knife cylinder 26.

OPERATION Referring now more particularly to FIG. 7, it will be seen that the cycle of operation of the machine is commenced by starting the electric motor 87 by pressing a start button which is generally in the upper left front of the machine. The motor 87 drive the flywheel 81 which stores sufficient energy to furnish adequate power to make the clamp and cut during a cycle. The operator in making the setup will employ the various guides and stops properly to position a stack of papers to be severed. Now, to make the cut, the operator presses two push button switches 98 and 99 recessed and substantially spaced further than the reach of an operators one hand at the front edge of the table 2. These push button switches when pushed open contacts 100 and 101 in line 102 and close contacts 103 and 104 in line 105, both lines 102 and 105 being connected to the electric power supply line 106. Limit switch 107 is opened when the knife reaches its lowermost position and limit switch 108 is opened when the knife reaches its top position. These limit switches are shown in FIG. 1 and it is noted that the limit switch 108 may be actuated by an extension 109 welded or otherwise secured to the arcuate crank link 21. Thus, when both push button switches 93 and 99 are actuated, power will be supplied through line 105, through normally closed limit switch 107 to energize solenoid 96 shifting the spool of valve 93 to cause the outlet of the pump 78 to be connected to hydraulic line 110 to supply hydraulic fluid through sequence valve 111 to line 112 leading to the blind end of clamp cylinder 43.

The sequence valve 111 may be provided with a spring loaded spool 113 having its end exposed to the hydraulic pressure in lines 110 and 112 so that hydraulic line 114 will remain closed to the hydraulic fluid in line 110 until the pressure in lines 110 and 112 reaches a suflicient preset value to overcome the pressure of the spring loading spool 113. The fluid being supplied through the line 112, the rod 51 is extended vertically upwardly rocking the lever 53 which engages the lever arm 55 rocking the shaft in a counterclockwise direction as viewed in FIGS. 5 and 6 bringing the binder clamp 30 downwardly to bear against the stack of papers. When the clamp engages the papers and the pressure in the cylinder builds up to such preset level, the sequence valve 111 now opens to allow fluid to pass into line 114 entering the blind end of the knife piston-cylinder assembly 26. During this operation, the return line 115 leading through the valve 93 to line 116 will be opened to return fluid to the reservoir 90. As the knife cylinder rod 25 is extended upwardly to rock the arcuate double ended lever 21 in a counterclockwise direction as viewed in FIG. 1 about the pivot 22, the link 19 will be pulled down, moving downwardly the knife bar 10 to sever the stack of paper.

When such lever 21 reaches its lowermost position as viewed at 32 in phantom lines in FIG. 1, the limit switch 107 will be opened signalling the completion of the cut and the control valve 93 then returns to its neutral position by the action of a spring. The pump output is now directed back to the sump and everything stops. Up until the closing of switch 107, the operator has been required to hold the contacts 103 and 104 closed. To release one of the push buttons 98 or 99 would stop the operation of the machine and to release both would reverse the operation by raising the knife and clamp since the switch 108 is now closed.

Now, when both switches 98 and 99 are released, solenoid will be energized and the pump output is directed from the pump into line causing the retraction of rods 51 and 25 respectively and the fluid in the blind ends of the cylinders 43 and 26 is then conveyed through the lines 112 and 114 through the valve, through line 116 and back to the sump.

When the knife reaches the top position, the limit switch 108 is opened and the valve then again returns to its neutral position. In this up position, the knife will be mechanically propped up by the positions of the pivots 20 and 22 so the knife cannot descend due to hydraulic a1 ure.

When the parts are in the last described] position, the operator can, if he wishes, bring down the binder clamp without affecting the knife. He merely steps on the treadle 44 and as the treadle moves downwardly, so does the clamp in synchronism. The springs 64 and 65 will automatically return the treadle and clamp to its up position should the operators foot be removed therefrom.

It can now be seen that there is provided a paper cutting machine wherein an energy storage means is provided enabling the use of a smaller and thus less expensive motor than would otherwise be required yet still furnishing sufficient power to actuate both the binder clamp and the cutter during a complete cycle of the machine. Also, with the unique treadle arrangement not physically connected to the hydraulically operated mechanism for actuating the binder clamp, it is possible manually to operate the binder clamp without disturbing the hydraulic pistoncylinder assembly.

Moreover, with the particular linkage employed, it is possible for the operator to synchronize the operation of the treadle with the movement of the binder clamp precluding the inadvertent placement of a hand or finger in the path of the clamp being brought down by the treadle. Another important safety feature is the mechanical linkage actuating the knife which mechanically props up the knife in its retracted position precluding the dropping of the knife due to a failure or seepage of the hydraulic system. Moreover, with the knife actuating linkage, a smaller knife actuating piston-cylinder assembly may be employed to obtain the same cutting pressure which would otherwise be obtainable with a larger piston-cylinder assemly connected directly to the knife bar.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I, therefore, particularly point out and distinctly claim as my lnventlon:

1. A paper cutting machine comprising a hydraulically operated binder clamp operative to clamp a stack of papers or the like in position to be severed, a hydraulically operated knife adapted to sever the thus clamped stack of papers, link means operatively connecting: said binder clamp with a hydraulic motor, means operative manually to operate said binder clamp without disturbing said hydraulic motor and spring pressure means operative uniformly to resist actuation of said clamp when thus operated manually.

2. A machine as set forth in claim 1 including treadle means operatively connected to said binder clamp whereby an operator can selectively operate said binder clamp either by said hydraulic motor or by said treadle means.

3. A machine as set forth in claim 1 including a binder clamp actuating shaft, said hydraulic motor being connected to said binder clamp actuating shaft by means of a freely rotatable crank link, and arm means on said actuating shaft operative to be engaged by said crank link to rotate said actuating shaft in response to energization of said hydraulic motor, said spring pressure means being operative uniformly to resist the rotation of said shaft and thus the actuation of said clamp.

4. A machine as set forth in claim 3 wherein said spring pressure means acts on the end of said arm means with a moment arm Which decreases as such spring pressure increases.

References (Cited by the Examiner UNITED STATES PATENTS 2,649,153 8/1953 Barley 83-380 FOREIGN PATENTS 291,231 5/1928 Great Britain.

WILLIAM W. DYER, 111., Primary Examiner.

L. B. TAYLOR, Assistant Examiner. 

1. A PAPER CUTTING MACHINE COMPRISING A HYDRUALICALLY OPERATED BINDER CLAMP OPERATIVE TO CLAMP A STACK OF PAPERS OR THE LIKE IN POSITION TO BE SEVERED, A HYDRAULICALLY OPERATED KNIFE ADAPTED TO SEVER THE THUS CLAMPED STACK OF PAPERS, LINK MEANS OPERATIVELY CONNECTING SAID BINDER CLAMP WITH A HYDRAULIC MOTOR, MEANS OPERATIVE MANUALLY TO OPERATE SAID BINDER CLAMP WITHOUT DISTURBING SAID HYDRUALIC MOTOR AND SPRING PRESSURE MEANS OPERTIVE UNIFORMLY TO RESIST ACTUATION OF SAID CLAMP WHEN THUS OPERATED MANUALLY. 